add simple edit page

To do:
- Add link for admin users and self user on user display page to
  reach the user edit page
- Create the actual catching functin to update the user (ignoring
  the password field on empty fields)
add conditional "Edit User" link to user page
update user creation, finish user editing

Fixed bug in user creation that was causing the string "NULL" to be set to
empty images and shortbios instead of the intended actual null value.
Finished user editing, and should be complete.  Hopefully nobody locks
themselves out of their accounts.